Shallow banks created by seagrasses restrict tidal flow into and out of the southern parts of the bay, further preventing dilution of waters in the upper reaches.

The most saline parts of the bay are Hamelin Pool, the southern part of L’haridon Bight and the southern extremes of Freycinet Harbour. These areas are hypersaline – almost twice as salty as the open ocean. The northern part of the eastern gulf and almost the entire western gulf are metahaline – up to 1.5 times as salty as the open ocean.

Hypersaline and metahaline waters are unusual in ocean environments and Shark Bay is one of the few marine environments in the world with hypersaline waters. Exuma Cays in the Bahamas is another.

The geological processes creating hypersaline waters and unique ecosystems they support are among the features that lead to Shark Bay’s World Heritage listing. Following is an explanation of this presented on an interpretive panel.

Salinity of Shark Bay

The geological processes creating hypersaline waters and unique ecosystems they support are among the features that lead to Shark Bay’s World Heritage listing.

Salinity

About Shark Bay

The shoreline of Shark Bay has a ‘W’ shape formed by the Edel Land peninsula and Dirk Hartog Island to the west, Peron Peninsula in the centre, and the eastern coastal strip. Edel Land is typified by rocky limestone and long, white sand dunes.